Piano sounding-board.



A. KRIEGHOFP.

PIANO SOUNDI'NG BOARD.

APPLIOATION FILED MAR.12, 1908.

`910,828. Patented Jan. 26, 1909.

7//1/1, liria/m r yet another form being subject fvidedl at its backwith a reinforce ANTON KBIEGHOFF, OF CC NCRD, NEW HAMPSHIRE.

No. 910,&28.

Speeficator. of Letters Patent.

Application filed harch 12, 1908.

Patented Jan. :26, 1909. Serial ne. 420.537.

To all whom may concer':

h Be it known that I, ANTON KmseHorF, 'a citizen of the United States,and resident of Qoncord, county of Merrimack, State of New Hampshire,have invented an Improvement in Eiao Sounding-Boards, of which the followng description, in connection with the accompanyng drawing, is aspecifioation, like letters on the drawing representing iike parte.

This. inyention has for its object the production-'of novel means forsounding board of a piano and for eiecting the required eonvexty ofboard, 'the Construction and arrangement being such that a very rich,clear and full tone can be produced the sounding-board to adjustment atall times; 4 My mvcnton is adapted for use in any kind of a piano, andespecially in those pianos where, byreason of limited s ace thesounding-board must necessarily be of smaii dimensions, for by myinventon I am-enabied to produce with a smallsounding-board a toneclosely approaching in nese and clearness the tone of alarge piano,while the use of myt invention will great-ly im' ro've any piano.

The various novelfeatures'of my invention will-be fully described in thesubjoned 'specifieation and particularlypointed out in the followingclaims.

-Figure 1 is a back View of the nietahia' string plate, soundng boardand tensionproducing means embodying one form of my nvention Fig. 2 is asection on the line 2-2, Fig. 1,-

3 a detal showing my invention with a different form of resiiientmembers by means of which the requisite convexity of the sounding-boardis efi'ected; Fig. 4 is a similar detail illustrating of the resilientmembers.

Reterrng to the drawings, the soundingboard b of suitable shape andcontour is prob', formed in practice by gluing to the back of the boardstrps of maplewood or other su table mat-eria adjacent its edge but setin therefrom suflciently to 'ieave a portion of the sounding-boardslightly overhanging the reint'orce as at b The overhang u board restsupon a bear-ing formed preferabiy ona metallic frame, such for instanceas. the stringlato F, which may be of any desired shape and structure,shown partly in dotted supporting the the soundingas shown;

resonance, fuH- in side elevation' b? of the soundinglines Fig. 1.. as arib or lip f* on the string-plate F and corresyonding in contour to thatof the overhang the bearingbeing shown in dotted ines Fig. 1 thesounding-board is interposed in front of the piate. By this construetionthe only part of the sounding-board in engagement with the piate F isthe overhang or extreme edge 6 so that practically the entiresounding-bcard is free to vibrate under the influence of the soundwaves.

The sounding board is interposed between the metaliio plate F and'apressure treme P, which conveniently made as a casting and prefer'ablyciosely contorms in shape 'to the soundngdoard. Said ?rame P secured tothe piate F by suitabie connections, herein shown as screws p, whichhave no engagement or connection with the sounding-board, the framebeing herein shown in hjig. l as having extensions p at certain porclearthe edges of the board.

' Between the frame P and the soundin board I insert resilient means.which bear r against the board at'its hack, and within the hearing fas'here'n shown, said means being iiiustrated as a series of sprngs. InFgs. l and 2 they -are shown as small ellpticai springs m, attached tothe frame P by screws, as at m and pressing against-the back'oi therenforce b The hearing is preferably made ,tions to enablethe connectngmembers g) to The required fiex'ng and 'convexity of the soundmg-boardseffected by the acton ot v the resiient members m ressino a ainst theboard. This may be attainedby mak'n the members m of such tension m thefirs nstanee, for a given fixed distance between the frame P and piate Fwhen assembled, that when the frame is in place by the connections p theexpensive tendency of the members m compressed between thesounding-board and the frame P will at once properly' fieX thesounding-board toward the string-plate The flexing is more con venientlyefiected, how'ever, by setting-up so positionedand-held saidconnection's to draw the t'rame P and the plate F toward each other'asmuch as may be desired, according to circumstances, so that theccmpressve action thereby imparted to the flexng members m will betransmitted by them to ti e s'oundingboard. towever this fieXing actionof the fiexing members is attained ,the sounding-boaid will be-conVeXed,

as the said members act upon the board at one side of the hearing f aswill be manifest, and by adjustment of the connections 1) the conveXitymaybe varied as required,

It will be observed that there is no rigid connection between thesounding-board and the plate F, as the edge of the board merely restsagainst the bearing f and the resilient members m press against theboard and act between the board and iframe P. An elastic contact is'thusprovided for ali' engaged portions of the sounding-board within theoverhang 11 and the vibrations of the board thus are free to act throughits entire surface up to its very edge.

The shape and general Construction of the pressure {rame can be variedto suit different circumstances, and the number and structure of thefieXing members m can be varied as may be necessarjgas iong as they areso located 'with relation to the other parts of the structure as toimpart the desired con vexity to the sounding-board.

In F10`. 3 I have shown the fiexin mem- D bere as spral springs mhearing at their free ends upon tne back or the reinforce b and at theirOther ends attached to the pressure-frame P.

A bow-spring form is shown at m in Fig. 4, the free ends of each boweontacting with the back of the reinorce of the soundingboard.

lt Will be manifest that the particular location of the connections pmay be changed, and I may if desired omit the fleXing members alongcertainportions of the soundingboard, provided the desired conveXity' isimparted thereto, without departing from my invention.

l make no claim heroin to the hearing rib or ridge, nor to the overhangof the sounding-board to rest against such rib, as those features areincluded in the claims of my United States Patent No; 885261, datedApril 21, 1908.

The sounding-board can be held from lateral movement relative to thepiate F by V means of pinsf on the plate entering loosely holes b seedotted lines Fig. 1, in the sounding-board.

My present invention is not restricted to the precise Construction andarrangement herein shown and described, as the same may be varied ormodified in di erent details by those skilled in the art withoutdeparting from the spirit and scope of my mvention as set forth in theannexed claims.

Having fully' described my invention, what I claim as new and desire tosecure by Letters Patent is r 1. The combination,wth a metailic plateand a sounding-board adacent thereto, of a hearing rib on oneto engagethe other and maintain separated the plate and the edge of the sounding-board, a pressure frame connected with the piate outside of therib and adjacent the back of the 'sounding-board, and resilient membersinterposed between the latter and the frame and actng upon thesounding-board inside the rib.

2. In piano Construction, a metallic plate having a bearing rib thereon,a pressure frame, adjustabie connections between' it and the frame,outside of the rib, a soundingboard between the frame and pinte andhaving its edge resting against the rib, and resilient fieXing membersinterposed between the ressure-frame and the back of the sounding-boardinside the hearing rib, to'form an elastic support for thesounding-board and to impart the requisite convexity thereto.

3. In piano Construction, a soundingboard, a metalho plate, a rib on oneto engage the other, a series of spring .members hearing against theback of the soundingboard inside the rib, and means to apply pressuresimultaneously to said members' and thence to the sounding-board, tofiex the iatter; p

e., in piano Construction, a soundingboard, a metalhc plate, a rib onone to en- -gage theother, a series ofspring members' hearing againstthe back of the soundingboard inside the rib, and means connected withthe plate independently of the sounding-board to apply pressure theretothrough phe sdpring members, 'to fieX the sounding oar v 5. Thecombination, with a string-plum,

,board and aeting upon-its back inside of its sustained edge, to fieXand thereby impart the requisite convexity to the sounding-board.

6. The combination, with a string-plate having a bearing thereon, of asoundingboard resting adjacent its edge against the hearing, resilientflexing members acting against the back of the sounding-board inside thebearing, and means to sustain said members independently of the.soundingboard and to impart to the letter flexing pressure through thesaid members.

7. A sounding-board, a hearing threfor at its edge, and resilientprcssure-producing means sustained independently of the sounding-boardand acting at a phrality of points upon the back thereof inside itshearing, to fiex and thereby impart the requisite convexity to thesounding-board.

8. The combination, with a string-pinte having a hearing thereon, of asoundingboard resting adjacent its edge against the said comcctionsnc'easng the pressure in1-,

parted to the sounding-bozrd by the said fiexng members. 9. Theeonbinaton, With a metallc plate a) and a. sou ndng board adjacentthereto, means toseparate the plate and the edge of the soundng-board, apressufie frame connected ith the plateand a'djacentthe back:

of the sounding-board, and resilent fle'xng 10 members interposedbetween the latter'and the f'ae and acting upon the soundingboard at0110 side of the Sep-&rating means.

In testnony Whereof, I have signed n' name to this specificaton in thepresence of two subscrbing witnesses.

' ANTON KRIEGHOF \-Vtnesses CHAs. GREMICK,

Amos J. PEAsLEE.

